Process for the obtention of juice from sugar cane



July 2, 1940. A. s. VILLASUSO PROCESS FOR THE DETENTION 0F JUICE FROM SUGAR CANE Filed Jan. 5, 1939 v 3mm flrmalndo $.Villd6uso,

Patented July 2, 1940 \rRooEss FOIt THE oniminoii oFf UI'oii "fl ppeasement 5, iseaf Serial nejziasss FRQM SUGAR: ,CANE

Armando S. Villasuso, Ingenio Concepcion, 1 Tucuman, Argentina l l i H i In Argentina October-1 31, 1938" 7 Claims. 1(01I 1127+43 This invention relates to imprevements in processes for the obtention of juicefrom sugarcane, and has for its main object an improved extractingfprocess whichenablesthe detention of maxifmum yield of raw material. 1 i j i In the extraction of sugar juice fromsugar cane, it is known to submit said canes, afterthe leaves have been removed tolthe action of the t mill for; the crushing thereof; as a result of this 10 operation and the compression exerted thereby,

the sugar, juice is separated from the raw material, leaving as a residue a solidjmaterial known I in the industry as bagasse, of secondary, appliy cation. M H J i The sugar juice obtained isthen submitted to the chemical action of lime, in a milk condition, mainly for the purpose of neutralizing the free acidity thereof, after which it issubmitted to the action of heat which causes the coagulation of certain components and facilitates the subsequent evaporation of the Volatile products, thereby rendering said juice ready to be submitted to defecation or clarification. I i i Thislatter operation is carried out in suitable defecating for clarifying tanks where the juice is allowed to stand for a certainlperiod of time, and I through decantation said juice is arranged in the form of layers constituted by foainandplear t juice, while the heavier substances precipitateto Bl) the bottom oiisaid tanks, in a sludge form known as scums; however, a, considerable part of the light substances such as fiber particlesismall bagasse), gums, waxes, etc., which remain, suspended in the juice, remain on thesurface of the B5 defecators, that is to say, level with the first layer and are carried out by the corresponding foam. When separating the rich and poor juices, for the purpose of submitting the,poor juice to a H double defecation, the scum and the foam of the i0 rich juice are incorporated to the poor juicein order to obtain a poorer residual scum. V 1

Itis know that the action oflime and heat on the substances contained inthe foam cause the formation of certain agents producinga loss of 15 saccharose. I j 1 a 1 On the other hand, the, foam forming the upper layer only overflows the defecators when; the free level of the juice rises, and as a result of this i a considerable portion of the rich juice is incor- 50 porated in the poor juice produced by the first defecation, and to the residual scum of the second defecation, which isprecisely what it is'desired to render poorer.

In order to obviate these drawbacks the present invention has been devised, which consists ments commonly employed the following specification.

mainly in keeping the foamland, the corresponcl"- ing scumperfecfly separated. from each other at all, times, incorporating said ream to the' bagasse ofthe mill most suitable tothepureness and richness "of said bagasse; and submitting the foamlessscumto any of the subsequent treat The invention also contemplates other objects which will becomeap'parent fromthe course of In order that the invention may bemore clearly understood and readily carried into practice, same has been illustrateclby way of example andin a preferred embodiment in the accompanying t drawing, whichfshows a schematic view of a plant for the extraction of cane juice, improved in ac cordance with the present invention.

, In said drawing, the reference characters la,

lb, lc an dbid indicate a seriesof mills for the purpose of crushing the sugar cane, which is carried to the. first of said mills by means of the feeding device formed by the pair of cylinders 2 and the inclined plane 3. Underneath eachof said mills are the trays 4a, 4b, 4c and 4d, from whichlead the tubes 5a, 5b, Bcand 5d, respectively, f orbthe discharge of thecorresponding uices. g The juice discharged by the conduit 5a, corresponding to the first mill, after passing through a filter 6, is pouredinto the lime vat 1a containing a suitable amount of lime milk, from where it leaves by the lower conduit 8ahaving interpolated therein a heater 9a, finally passingtothe reservoir llla wherein the clarifyingof said juice is efiectedby decantation In turn,fbelowthe discharge conduit 5ais a small conveyor l I, suitf ably combined with a plane I12, which again car ries the residual smalllbaga'sse or fibrous pardecantation or defecating tanksleave by the side 1 conduits [3a and l 36 starting fron'idifierent levels thereof. In turn, the scum or heavier substances are extracted through the conduits [4a and lb starting from the lower portion of said reservoirs, and finally the foams, which'due to their low ticles of the cane, to the first mill [a where they 1,

waxes, etc., in suspension, may be discharged together with the foam, extends upwardly leading again into any one of the mills forming the set, for example the first mill la, where the light sub stances are submitted to a new combined crushing and compression process, and after being incorporated to the bagasse formed therein, suffer the previously described successive operations.

Inturn, the first sediment or scum, which is eliminated through the lower conduit Ma is carried to the lime vat lb where it suffers. a further calcification followed by new heating in the heater 9b to pass into the second defecating, tank 10b where it suffers a new decantation, the sediment of which,forming the second scum, is collected by the lower conduit l4b for submitting same to the action of a centrifugal separator, press filter, third decantation or any of the commonly used subsequent treatments. V

The bagasse remaining as a residue from the first mill la is passed to the second mill. lb and the juices separated therefrom are discharged through the lower conduit 52), passing together with the first scum or sediment of the decantation tank Illa to the lime vat 'l'b, heater 9b and finally tothe second decantation tank I 01). In turn,ithe bagasse which has remained as a residue from the second mill is passed to the third mill I0, and the juice resulting from this opera.-. tion is discharged through the lower conduit 50, passing again to the first mill la where it is incorporated to the products treated" thereby; finally, the bagasse remaining as a residue of the third mill after having been suitably macerated with water is passed to mill Id and the resulting juice is discharged through the lower conduit d carrying same to the second mill lb, following therefrom the previously described circuit, while the bagasse remaining as final residue from said mill Id is separated and disposed of as fuel or for any other purpose.

The foam formed on the surface of the second decantation tank lflb and whichmay still contain some light products in suspension, is discharged through' conduit 15b, which is suitably connected to conduit 50, passing again to the first mill Ia for subsequent treatment; finally, the poor juice'extracted from the decantation tanklllb through the conduit I3b passes again to the lime vat 1a where it again suffers the operations described above.

By means of this process, the foams are at all times kept perfectly separated from the corresponding scums,- thereby obviating the abovementioned drawbacks.

While in the example represented a plant constituted by four sets of mills has been assumed, it is evident that'the number thereof, as well as'the number of lime vats and defecating tanks, may vary in accordance with the requirements of each case. i

a In turn, the foam coming from the decantation tank Illa, instead of returning to the first mill, may be carried to any of the mills more suitable for the richness of the bagasse being formed therein,'while the residual scum of the struction and detail may be introduced without departing from the scope of the present invention as clearly set forth in the appended claims.

What I claim is:

1. The process of extracting the juice from sugar cane which consists in subjecting sugar cane to a plurality of stages of crushing operations, collecting the juices from the operations in independent volumes, allowing each volume of juice to settle whereby lighter elements of the volume rise as foam and heavier elements settle as scum, conducting the foam from the first volume directly back to the first stage of crushing operation, conducting the scum from the first volume of juice into the second volume of juice, conducting the foam from the second volume of juice back to the first stage of crushing operation, and conducting thejuice of the second volume into the first volume of juice.

2. The process of extracting the juice from sugar cane which consists in subjecting sugar cane to, a plurality of stages of crushingoperations collecting the juices from the operations in independent volumes, allowing each volume of juice to settle whereby lighter elements of the volume rise as foam and heavier elements settle as scum, conducting the foam from the first V01- ume directly back to the first stage of crushing operation, conducting the scum from the first volume of juice into the second volume of juice,

conducting the foam from the second volume of juice back to the first stage of crushing operation, conducting the juice of the second V01- ume into the first volume of juicgsubjecting the mass of crushed cane from the second stage of crushing operation to a third crushing operation, and conducting the juice from the third stage directly back to the cane passing through the first stage.

3. The process of extracting the juice from sugar cane which consists in subjecting sugar cane to a plurality of stages ofcrushing operations, collecting the juices from the operations in independent volumes, allowing each volume of juice to settle whereby lighter elements of the volume rise as foamand heavier elements settle as'scum, conducting the foam from the first volume directly back to the first stage of crushof crushed cane from the second stage of crush-'- ing operation to further stages of'crushing operations, and conducting the juice from each of said further stages direct to the material passing through each second preceding stage.

S. VILLASUSO. 

